As used herein, "indicia" means a distinctive predetermined pattern which the manufacturer of an edible product wishes to have applied on the outer surface of a food product. Indicia includes "logo" which is an intelligible pattern as for example one or more letters, pictures or symbols. Indicia also includes marks which have a pleasing connotation to the consumer, as for example grill marks.
There is a long-standing need for an edible food product with a desired indicia on its outer surface. For example, food processors would like to have their edible product identified by their company logo to indicate high and consistent quality. Also, other types of indicia such as grill marks on frankfurters are desirable for esthetic reasons.
Frankfurters are prepared by processing of moist emulsion at elevated temperature and in a moist environment inside casing, usually manufactured from cellulose, i.e. cellulosic casings. The latter are typically supplied to the food processor in the form of shirred sticks, i.e. highly compressed pleats which may be on the order of 1/150 of their as-manufactured flat length. The shirred stick with one closed end is attached to a stuffing machine which deshirrs and deplugs the closed end of the stick whereupon emulsion is pumped into and fills the casing. The emulsion-filled casing is formed into short links and at high speed, e.g. 250 fpm as it is removed from the stuffing machine. The emulsion is cooked within the casing during the processing step to form a frankfurter. After processing, the cellulosic casing is peeled from the frankfurter outer surface using high speed equipment, e.g. 500 fpm, and the casing is discarded.
For high speed production, the moisture content of the cellulosic casing must be closely maintained during both the shirring and the stuffing steps. This is necessary so that the casing has the necessary flexibility for moving without breakage yet adequate physical integrity for mechanical handling during deshirring and stuffing. Plasticizers such as glycerine are also included in the casing to partially satisfy these requirements.
Those skilled in the food processing art recognize that it is not commercially practical to impart color indicia on frankfurters after processing and casing removal. The prior art has proposed this be done for example by searing the frankfurter to form grill marks, as taught in U.S. Pat. No. 4,384,006. One problem with this approach is the need for additional and complex high speed machinery to match the frankfurter production rate. Another problem is that searing requires penetration of the thin outer skin of the frankfurter, thereby creating a sanitation issue.
Another approach to providing an edible food body outer surface with color indicia is to form the indicia on the cellulosic substrate and then transfer the indicia to the food body outer surface during processing. There are a number of problems to this approach which have not been collectively overcome. The indicia must be formed of material which has been approved by governmental authorities for direct contact with food, and this requirement severely restricts the selection of constituents. Further, the indicia as applied to the substrate should have at least some degree of abrasion resistance. If for example the indicia-containing substrate is food casing to be shirred, the indicia must retain its integrity during extreme distortions of the substrate which are characteristic of the pleat-forming and compression steps of shirring, as well as pleat elimination and straightening out of the casing during the succeeding inflation and stuffing. Even if the casing is not shirred but instead rolled and fed to the stuffing machine as roll stock, there is considerable distortion by virtue of the bending and compression of the casing to form roll stock.
A further requirement is that the indicia must not cause transfer ("ink-offsetting") or even "blocking" during handling or storage of indicia-containing substrate, i.e. transfer or even adhesion to either the substrate or another indicia when different substrate portions are pressed together as for example in shirring, rolling or stacking.
Another requirement of any food casing color indicia system is that the indicia must have at least some degree of moisture insensitivity. That is, the color indicia is preferably insoluble in water at ambient temperature because the casing itself must contain substantial moisture in the as-manufactured condition, as previously explained. If shirring is to be employed, the casing is further moisturized during shirring. A color indicia which is even partially soluble in water would smear and could not transfer as a clearly defined sharp indicia.
Still another requirement of a food casing color indicia system is that the indicia must substantially completely transfer to the contiguous edible surface with sharp definition. Less than complete transfer would result in an indicia which has poor definition, unevenness or be too faint when compared with the surrounding surface. This occurs when one attempts to pass color indicia through the casing wall in the presence of moisture (from the outer surface to the inner surface) to the sausage during stuffing, as described in U. S. Pat. No. 2,301,564.
Color indicia may possibly be formed from dyes or pigments, but there are serious limitations with each approach. Water soluble dyes are extremely moisture sensitive, i.e. they tend to run away from the as-applied indicia leaving at best a fainter mark with poor definition. Solvent soluble dyes are not moisture sensitive but are not approved by governmental authorities for human consumption. On the other hand, organic pigments are unavailable in certain colors as for example brown, and in general are not approved by governmental authorities for human consumption.
An object of this invention is to provide an article comprising a substrate with a desired color indicia thereon which is approved for direct contact with food, moisture insensitive, and which is substantially completely transferable from the substrate to a contiguous edible surface.
Another object is to provide a processable food package comprising a casing filled with processable food in direct contact with the casing inner surface, the latter having thereon a desired color indicia which is substantially completely transferable from the the casing inner surface to the food outer surface during in-situ processing of the food.
A further object is to provide an edible food product having on its outer surface a desired color indicia.
A still further object is to provide a method for making processed food product in which a casing with a desired color indicia on its inner surface is stuffed with a processable food mass, the color indicia is substantially completely transferred to the food mass outer surface during food processing and the casing is thereafter removed from the processed food mass without loss of the color indicia on the food mass outer surface.
Other objects and advantages of this situation will be apparent from the ensuing disclosure and appended claims.